The Training in International Population and Health Sciences Program housed in the California Center for Population Research at UCLA is an ambitious and innovative program that will train a new generation of population scientists in Indonesia and Mexico. The foundation of the program is an exceptionally strong research base of extra-murally funded, inter-related and complementary projects that provide the ideal vehicle for interdisciplinary training in the population and health sciences. These large-scale research projects are the result of long-term investments in collaborative research projects by the US-based and international training faculty. The training program, which is designed to have the maximum impact on research and research capacity in the collaborating countries, has three main activities. First, long-term predoctoral trainees will enrol in Ph.D. programs at UCLA which are specifically designed for population scientists. These include programs in economics, public health and sociology. The programs provide the highest quality training in modern quantitative methods for population research. Second, medium-term training programs will be specifically tailored to the needs of population scientists from Mexico and Indonesia who will visit UCLA. The programs will enable the trainees to enhance and update their research-related skills while conducting their own and collaborative research. The medium- and long-term trainees will be integrated with the on-going research projects that are the research base for this application. Third, a series of short-term in-country training activities will contribute to the development of population research capacity in each of the collaborating countries. Some of the short-term workshops will emphasize data analysis and quantitative methods. Other short term training workshops will focus on emerging areas in population research where skill shortages are impeding the development of pioneering research in the population and health sciences. Trainees will receive instruction in the ethical conduct of population research. Special attention will be paid to recruiting outstanding minorities and to assuring that trainees return home to a productive research environment. The training program will significantly contribute to research capacity in both Mexico and Indonesia while also generating important benefits to the underlying research projects that form the foundation for this program.